B because the skater is constantly moving in the same speed to go in a circle .
pH is the measure of the concentration of hydrogen ions in a solution
Gases can be compressed, because they just take up the space surrounding them. The attractive forces between the particles in a gas are very weak, so the particles are free to move in random direction. They just move along until they collide, either with the walls of the container or with each other. Moreover, gases can be compressed because the particles are far apart and they have space to move into.
As we know by the first law of thermodynamics

here we know that
Q = heat given to the system

W = work done by the system
now here we can say


now we can say that heat will be given as

now here we can say that Jin does the error in his first step while calculation of change in internal energy as he had to subtract it while he added the two energy
So best describe Jin's Error is
<em>B )For step 1, he should have subtracted 78 J from 180 J to find the change in internal energy. </em>
The circuit is no longer closed.